A VPlan contains multiple live-ins without underlying IR, like VFxUF or
VectorTripCount. Trying to infer the scalar type of those causes a crash
at the moment.
Update VPTypeAnalysis to take a VPlan in its constructor and assign
types to those live-ins up front. All those live-ins share the type of
the canonical IV.
PR: https://github.com/llvm/llvm-project/pull/80723
This patch adds initial type inferrence for VPValues. It infers the
scalar type of a VPValue, by bottom-up traversing through defining
recipes until root nodes with known types are reached (e.g. live-ins or
load recipes). The types are then propagated top down through
operations.
This is intended as building block for a VPlan-based cost model, which
will need access to type information for VPValues/recipes.
Initial testing is done by asserting the inferred type matches the type
of the result value generated for a widen and replicate recipes.
